Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quantas temporadas têm totais de pontos de N/A?
 ###Tabelas: CREATE TABLE season-by-season_results (season-by-season_results_id AUTO_INCREMENT PRIMARY KEY, Season VARCHAR, Games INT, Won INT, Lost INT, Tied INT, Points INT, Winning Pct. % VARCHAR, Goals for INT, Goals against INT, Standing VARCHAR) CREATE TABLE indian_telly_awards (indian_telly_awards_id AUTO_INCREMENT PRIMARY KEY, Year INT, Category VARCHAR, Character VARCHAR, For The Show VARCHAR, Result VARCHAR) CREATE TABLE 0_–_728_throw_3_times (0_–_728_throw_3_times_id AUTO_INCREMENT PRIMARY KEY, 1st throw INT, 2nd throw INT, 3rd throw INT, Equation VARCHAR, Result INT) CREATE TABLE career_summary (career_summary_id AUTO_INCREMENT PRIMARY KEY, Season INT, Series VARCHAR, Team VARCHAR, Races INT, Wins INT, Poles INT, F/Laps INT, Podiums INT, Points VARCHAR, Position VARCHAR) CREATE TABLE democrats (democrats_id AUTO_INCREMENT PRIMARY KEY, Candidate VARCHAR, Total Receipts INT, Loans Received INT, Receipts w/o Loans INT, Money Spent INT, Cash On Hand INT, Total Debt VARCHAR, Cash on Hand Minus Debt INT)  
SELECT COUNT Season FROM career_summary WHERE Points = N/A